Re: [PATCH] mm: kmemleak: Ensure that the task stack is not freed during scanning

[Andrew Morton]

On Wed, 12 Oct 2016 10:57:03 +0100 Catalin Marinas <catalin.marinas@xxxxxxx> wrote:

> Commit 68f24b08ee89 ("sched/core: Free the stack early if
> CONFIG_THREAD_INFO_IN_TASK") may cause the task->stack to be freed
> during kmemleak_scan() execution, leading to either a NULL pointer
> fault (if task->stack is NULL) or kmemleak accessing already freed
> memory. This patch uses the new try_get_task_stack() API to ensure that
> the task stack is not freed during kmemleak stack scanning.
> 
> Fixes: 68f24b08ee89 ("sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK")
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Andy Lutomirski <luto@xxxxxxxxxx>
> Cc: CAI Qian <caiqian@xxxxxxxxxx>
> Reported-by: CAI Qian <caiqian@xxxxxxxxxx>
> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>

I'll add

Cc: <stable@xxxxxxxxxxxxxxx>    [4.8.x]